Помогите решить примеры по математике:1)9/16 * (21 1/3х - 4/15у)-7/23 * (2/37х)-2 4/21у2) (1 24/25 : (- 1,4)+(-2 4/9) : (-11/18)) * 5/13

1)9/16 * (21 1/3х - 4/15у)-7/23 * (2 3/7х-2 4/21у)
9/16*64/3x-9/16*4/15y=12x-3/20y
7/23*23/7x-7/23*46/21y=x-2/3y
12x-3/20y-x+2/3y=11x+11/60y=11(x+1/60y)
2) (1 24/25 : (- 1,4)+(-2 4/9) : (-11/18)) * 5/13=1
1 24/25 : -1.4=49/25 * -10/14=-7/5
-2 4/9 : -11/18=22/9*18/11= 4 
-7/5+4=-7/5+20/5=13/5
13/5*5/13=1